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Probiotics may have benefits for ulcerative colitis, but not Crohn’s disease

By Joan Stephenson

NEW YORK (Reuters Health) - A probiotic called VSL#3 may be effective in inducing remission in active ulcerative colitis (UC), according to findings from a new systematic review and meta-analysis.

However, no benefits were found for probiotics in treating active Crohn’s disease (CD) or preventing relapse after remission.

VSL#3, a mixture of eight strains of lactic acid-producing bacteria, “may be effective in inducing remission in active ulcerative colitis,” corresponding author Dr. D. J. Gracie, of Leeds Gastroenterology Institute at the University of Leeds, in the UK, told Reuters Health by email.

However, in CD, use of probiotics “is poorly described in a limited number of randomized controlled trials, and cannot be advocated,” he cautioned.

Both of these types of inflammatory bowel disease (IBD) are thought to result from interaction of genetic and environmental factors. The latter include changes in the intestinal microbiome, typically a relative increase in pro-inflammatory species and decrease in anti-inflammatory species.

“The use of probiotics in gastrointestinal disease is well studied in IBD populations where there is an existing evidence base that supports their use,” Dr. Gracie said. Given the high prevalence of functional symptoms in IBD, “this was a logical systematic review and meta-analysis to undertake.”

The researchers identified 22 eligible randomized controlled trials that recruited adults with UC or CD and compared the use of probiotics with use of 5-aminosalicylates (5-ASAs) or placebo.

Fourteen of the trials investigated the efficacy of probiotics in inducing remission in active UC (eight trials with 651 patients) or preventing relapse in quiescent UC (six trials with 677 patients). The other trials investigated the efficacy of probiotics vs. placebo in inducing remission in active CD (two trials with 37 patients), preventing relapse of quiescent CD (two trials with 195 patients), or preventing relapse of CD in remission following surgical resection (four trials of 333 patients).

There was no benefit of probiotics over placebo in inducing remission in active UC, but an analysis of the three studies that used VSL#3 found that patients who received the probiotic were more likely to experience remission than those receiving a placebo, the researchers reported online June 27 in Alimentary Pharmacology and Therapeutics.

In those three studies, 91 of 162 patients (56%) who received VSL#3 failed to achieve remission compared with 118 of 157 (75%) of patients who received placebo (risk ratio of failure to achieve remission, 0.74).

The findings demonstrate “that the probiotic VSL#3 may have beneficial effects in terms of inducing remission in active UC,” the researchers write.

In three trials involving 555 patients that compared efficacy of probiotics vs. 5-ASAs in preventing UC relapse, the two interventions appeared equivalent (RR, 1.02).

However, probiotics did not demonstrate a benefit in inducing remission of active CD or in preventing relapse of quiescent CD or CD after surgically induced remission.

“These findings highlight the potential benefit of probiotics in UC, but also underline the paucity of studies, particularly in Crohn’s disease,” pointing to the need for further randomized trials, particularly in CD, Dr. Gracie said.

“Moreover, correlation of the effects of these preparations on disease activity in conjunction with microbiome/metabolomic/proteomic assessment may provide further insight into the mechanisms by which these therapies may (or may not) be effective,” he said.

The systematic review confirms the conclusions of three successive conferences on the use of probiotics (the Triennial Yale/Harvard Workshop on Probiotic Recommendations), “that their efficacy in IBD is limited to ulcerative colitis, but has failed in Crohn’s disease,” said Dr. Levinus A. Dieleman, director of IBD Clinical Research at the University of Alberta in Edmonton, Canada.

Dr. Dieleman, who was not involved in the current study, noted that in his own research, he has found that not all probiotics are the same and their effect is strain- and host-dependent.

Use of VSL#3, the only probiotic cocktail effective in UC, remains limited by its relatively high cost and the lack of reimbursement for probiotics by health insurance companies, Dr. Dieleman said. In contrast, most drugs for the condition are covered by health care plans.

At the same time, more than half of patients with IBD use several strains of over-the-counter probiotics, he said, noting that many preparations contain one or several strains of unproven efficacy and in amounts well below those used in randomized controlled trials.

Use of probiotics and other “microflora-altering products” to manipulate the gut microbiome holds promise for preventing and treating mild forms of inflammatory and metabolic disorders, but “a rational development” of these products that includes in-depth research into their protective mechanisms is needed, Dr. Dieleman said.

The use of these products by IBD patients “should be dictated by scientific evidence, and not by who is best at advertising popular, false health benefits,” he said.

The study had no commercial funding and authors declared no conflicts of interest.

SOURCE: http://bit.ly/2tO8Nvw

Aliment Pharmacol Ther 2017.

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